Bicycle frame

ABSTRACT

A bicycle assembly can include a bicycle frame that can have a main frame, a sub-frame and a shock absorber. The sub-frame can move in relation to the main frame and the shock can be used to regulate that relationship. A extension body can be used to establish a rear pivot point of the shock absorber. In some embodiments, the extension body can also be used to adjust the length of the combined shock absorber and extension body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to bicycle suspension systemsand frame assemblies. In particular, the present invention relates toconfigurations for rear suspension assemblies and mounting arrangementsfor rear suspension assemblies suitable for use in connection withoff-road bicycles.

2. Description of the Related Art

Off-road bicycles, or mountain bikes, may be equipped with front andrear suspension assemblies operably positioned between the frame of thebicycle and the front and rear wheels, respectively. Providing front andrear suspension on a mountain bike potentially improves handling andperformance by absorbing bumps, and other rough trail conditions, whichmay be encountered while riding off-road. However, because mountainbikes are typically pedal-driven, i.e., use the rider's power output topropel the bicycle, the provision of rear suspension, especially, mayundesirably absorb a rider's power output, resulting in wasted effort.

Accordingly, rear suspension systems commonly incorporated onengine-driven vehicles, such as motorcycles, have proven undesirable foruse with pedal-driven vehicles, such as mountain bikes. In addition,because a mountain bike is propelled solely by power output from therider, it is desirable that the rear suspension assembly be lightweight.Rear suspension systems of engine-driven vehicles commonly emphasizestrength over weight and, therefore, have not been widely incorporatedon mountain bikes.

Mountain bike rear suspension designs, utilizing multiple linkagemembers, are currently used and are often effective at isolatingpedal-induced and brake-induced forces from acting on the rearsuspension. However, one problem associated with prior mountain bikerear suspension designs involves placement of the rear shock absorber.Due to the relatively complex nature of common mountain bike rearsuspension assemblies, the rear shock absorber cannot always be placedin an optimal position.

SUMMARY OF THE INVENTION

There exists a continuing need to develop new configurations for theplacement and mounting of rear suspensions on bicycle frames. Along withthis need, there also exists a need to develop new designs for shockabsorbers and shock absorber mounting equipment to facilitate the newconfigurations for the placement and mounting of rear suspensions onbicycle frames.

According to some embodiments, a bicycle assembly can comprise a mainframe, a sub-frame configured to rotate with respect to the main frame,and a shock absorber. The main frame can include a seat tube, a headtube and an intermediate tube connecting the seat tube and the headtube. The shock absorber can have first and second opposing ends andfirst and second eyelets at each end. The first eyelet at the first endis preferably connected to the main frame. The bicycle assembly mayfurther include an extension body comprising a first end connected tothe shock absorber at the second eyelet and a second end comprising apair of extension arms, each extension arm connected to the sub-frame,wherein a rear pivot of the shock absorber is defined by a connectionpoint between each extension arm and the sub-frame, and the rear pivotconfigured to be at the sides of a rear wheel.

The first end of the extension body in some embodiments can receive thesecond eyelet within the extension body and the axis of the center ofthe second eyelet is at least about 15 degrees offset from the axis ofthe center of the first eyelet, such that the extension body forms arigid, non-rotating connection with the second eyelet.

The bicycle assembly according to some embodiments can further include afastener securing the extension body and the second eyelet of the shockabsorber. A spacer can also be provided to be within the second eyelet,the spacer having a hole to receive the fastener. In some embodiments,the hole in the spacer is off-center such that the position of spacerwithin the eyelet allows for the adjustment of the length of combinedshock absorber and extension body.

According to some embodiments the bicycle assembly can further comprisea fork, a saddle, the rear wheel and/or a front wheel and the sub-framecan comprise a pair of seat stays and a pair of chain stays. Further insome embodiments, the axis of the center of the second eyelet is atleast about 45, 60, or 80 degrees offset from the axis of the center ofthe first eyelet.

A bicycle assembly can include a bicycle frame and the bicycle frame caninclude various components. Some of these components can include a mainframe, a sub-frame configured to rotate with respect to the main frame,a shock absorber configured to regulate the relationship between themain frame and the sub-frame, and an extension body. Certain main frameshave a seat tube, a head tube and a top tube connecting the seat tubeand the head tube. The shock absorber can include a first eyelet toconnect to the main frame and a second eyelet. The extension body canhave various configurations. For example, a first portion can beconfigured to connect to the second eyelet of the shock absorber andform a rigid non-rotating connection, and a second portion can comprisea pair of extension arms. Further in some embodiments, the extensionarms can be configured to straddle a rear wheel such that a rear pivotof the shock absorber is at the sides of the rear wheel, the front pivotbeing at the first eyelet of the shock absorber.

In some embodiments, the second eyelet of the shock absorber isperpendicular to the axis of rotation of both the front and rear pivots.The second eyelet can be offset 90 degrees from the first eyelet.

According to some embodiments, the bicycle assembly can further comprisea fastener to secure the extension body and the second eyelet of theshock absorber. Further a spacer can be used within the second eyelet.The spacer can have a hole to receive the fastener. The hole in thespacer can in centered or off-center. Where hole in the spacer isoff-center, the position of spacer within the eyelet can allow for theadjustment of the length of combined shock absorber and extension body.Further, the extension body can also be configured to be adjustable. Forexample, the extension body can include two or more extension body holesfor receiving the fastener and allowing for further adjustment of thelength of combined shock absorber and extension body by selection of theextension body hole.

Some embodiments of a bicycle assembly can comprise a main frame havinga seat tube, a head tube and a top tube connecting the seat tube and thehead tube. The bicycle assembly may further include a sub-frameconfigured to rotate with respect to the main frame, the frame beingconfigured to regulate the relationship between the main frame and thesub-frame with a shock absorber having a first eyelet for connecting tothe main frame and a second eyelet. In some embodiments, the bicycleassembly can also include an extension body, a fastener and a spacer.The extension body can have a first portion configured to connect to thesecond eyelet of the shock absorber and a second portion. The fastenercan be used to secure the extension body and the second eyelet of theshock absorber. The spacer can be configured to reside within the secondeyelet. The spacer can have an off-center hole to receive the fastener,such that the position of spacer within the eyelet allows for a user toadjust a length of the shock absorber and extension body.

In some embodiments, the second portion of the extension body cancomprise a pair of extension arms configured to straddle a rear wheelsuch that a rear pivot of the shock absorber is at the sides of the rearwheel, the front pivot being at the first eyelet of the shock absorber.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages are described belowwith reference to drawings of preferred embodiments, which are intendedto illustrate but not to limit the present invention.

FIG. 1 is a side view of an embodiment of a bicycle frame.

FIG. 2 illustrates a perspective view of the bicycle frame of FIG. 1.

FIG. 3 is a perspective view of an embodiment of a shock absorber and anextension body.

FIG. 4 shows an exploded partial view of the shock absorber andextension body of FIG. 3.

FIG. 5 is a cross-sectional view of the connected shock absorber andextension body of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A bicycle, as shown in FIG. 1, has a bicycle frame 10 with a rearsuspension system. The bicycle frame 10 is made-up of a main frame 2, ashock absorber 4 and a sub-frame 6. A main frame 2, according to someembodiments, has a seat tube 21, a top tube 23 and a head tube 25. Thetop tube 23 can connect the seat tube 21 and the head tube 25. A seatpost 8 with an attached saddle 12 can be installed in the seat tube 21.A steering post or column 14 which connects the handle bars 16 and thefork 18 can be installed in the head tube 25. The fork can support thefront wheel 30. Some embodiments may further include a down tube 27 anda bottom bracket 29. The down tube 27 can connect the bottom bracket 29and the head tube 25. A crank 20 can be installed into the bottombracket 29 to which pedals 22 can be attached.

According to some embodiments, the main frame 2 can further include oneor more gussets or cross tubes 24. The cross tubes can connect variousparts of the main frame 2. For example, in FIGS. 1-2, the cross tube 24connects the seat tube 21 and the top tube 23. Cross tubes 24 canincrease the frame's stability and allow for additional design features,such as a downward sloping top tube 23.

As mentioned, the bicycle frame 10 can also include a sub-frame 6 and ashock absorber 4. The sub-frame 6 is movable relative to the main frame2. The shock absorber 4 regulates movement between the sub-frame 6 andthe main frame 2. A pivot axis P is shown in FIGS. 1-2 to illustrate thevarious points of rotation on the bicycle frame 10.

The sub-frame 6 can include a pair of seat stays 32 and a pair of chainstays 34. Each seat stay 32 can connect with a corresponding chain stay34 and can support a rear wheel 30. This connection can be fixed orpinned to allow for rotation. In some embodiments, the chain stays 34are hingedly connected to the main frame at or near the bottom bracket29.

A link 36 can also be used to connect the main frame 2 and sub-frame 6.In some embodiments, the link 36 is pivotally connected to the mainframe 2 and sub-frame 6. In some embodiments, the link 36 can beattached to the shock absorber 4, instead of, or in addition to, eitherthe main frame 2 or the sub-frame 6.

A forward end of the shock absorber 4 is shown rotatably coupled to themain frame 2 for a rotation about a pivot axis P. This pivot axis P canbe defined by a shock mount 38. A rearward end of the shock absorber 4is coupled to an extension body 40 which is rotatably coupled to thesub-frame 6 and, more specifically, to a shock mount assembly 42 for arotation about a pivot axis P. The shock mount assembly 42 can include afirst arm 44 and a second arm 46 that, along with the chain stays 34,define an essentially triangular shape in plan view. The shock absorber4 can be used to control the amount of movement between the main frame 2and the sub-frame 6 and the rate of change in their relationships.

Further relating to the movement of the different parts of a bicycleframe, pivot axis P is used in some of the figures, such as FIG. 2, toshow the various pivot points where some of the different components ofthe bicycle frame 10 are connected. The pivot axis P can defineconnection points which in some embodiments and in some locations caninclude bushings, or bearings, though this is not required. For example,in some embodiments there are cartridge ball bearings at the pivot axisP, where the extension body 40 connects to the sub-frame 6.

Though one configuration of a bicycle frame 10 is shown, those skilledin the art understand that various configurations are possible and mayalso be desirable.

Turning now to FIGS. 3-4, a shock absorber 4 and extension body 40 areshown. The shock absorber 4, according to some embodiments, can be acommonly available fluid and/or coil spring shock absorber. In someembodiments, the fluid can be oil and/or air.

The shock absorber 4 shown has an eyelet 48, 50 at either end to attachthe shock absorber 4 to a bicycle frame as part of a rear suspension.Though the shock absorber can be a commonly available shock, the shockabsorber 4 used here has been adjusted or modified, such that the reareyelet 50 is perpendicular to the typical axis of rotation and, in fact,the rear eyelet 50 is not used for rotation. Thus, as can best be seenin FIG. 4, the center axis A₁ of the opening of the rear eyelet 50 isoffset 90 degrees from the center axis A₂ of the opening of the fronteyelet 48. This can generally be done by simply rotating the eyelet 50and shaft of the shock absorber by hand in relation to the other eyelet48 to reach the desired position and orientation.

The shock absorber 4 can also have adjustment controls 52. Theadjustment controls 52 can include adjustments for dampening, rebound,pressure and other adjustments. The adjustment controls can includeadjustment knobs, a Schrader or Presta valve, and/or a preloading ringas are known in the art.

The extension body 40 has a first end 54 and a second end 56. The firstend 54 can be configured to receive an eyelet 48, 50 of a shock absorber4 and the second end 56 can be configured to connect to a bicycle frame10. In some embodiments, the second end of the extension body 40 and thebicycle frame 10 can be pivotally connected. The connection point mayinclude bearings, bushings or other features to reduce friction andallow for smooth rotation and movement. The extension body 40 can beused to effectively increase the length of the shock absorber 4. Thisincreased length of the shock 4 can change the pivot points at which theshock absorber 4 is attached to the bicycle frame 10 and can therebychange the relative motions that the shock absorber 4, main frame 2 andsub-frame 6 experience in relation to one another.

In some embodiments, the second end 56 of the extension body includes apair of extension arms 58. Each extension arm 58 can have an eyelet 60.The extension arms 42 can allow the shock absorber 4 to span part, orall, of the rear wheel, the seat tube or other parts of the bicycle. Inthis way, extension arms 58 allow the extension body to, not only movethe rear the pivot location of the shock absorber 4 to a more distantlocation, but also to locate the rear pivot to a spot not previouslyavailable or possible. For example, the extension arms can move thepivot location to the sides of the wheel, where previously, the rearpivot of the shock absorber could only be located in front of the rearwheel. The extension arms also provide additional benefits as detailedbelow.

Another feature of certain embodiments of extension bodies 40, is aninner surface 62 defining a cavity configured to receive an eyelet 48,50 of the shock absorber 4. The inner surface 62 can be contoured orshaped to receive the eyelet. Preferably, the inner surface 62 can beshaped to receive the eyelet of any of the many commonly available orcustom shock absorbers. In some embodiments, the inner surface can becontoured, such as to form a round cavity shaped to closely match theoutside surface of the eyelet. In other embodiments, the extension body40, and/or the first end 54 of the extension body can be hollow to allowfor various different configurations of eyelets and shock absorber endsto fit within the extension body 40. In some embodiments, the innersurface can closely fit the eyelet so as to restrict rotation and/orother movement between the extension body and the shock absorber. Insome embodiments, a looser fit can be provided. This can permit theselection of a wider variety of shape of mating eyelets and/or shockabsorbers.

In some embodiments, the inner surface 62 can be configured to receivean eyelet 50 of a shock absorber 4 that has been rotated or modified tobe offset 90 degrees from the typical orientation of the eyelet, such as90 degrees from the orientation of the other eyelet 48. In someembodiments, the inner surface 62 is formed to create a cavity closed atall but one end. In some embodiments, the inner surface 62 forms acavity that is open at the front and back of the cavity, where thecavity passes through the extension body 40 (FIG. 5).

As shown in FIGS. 3-4, the first end 54 of the extension body 40 can behollow and can include an opening or slit 64. The slit 64 can extendfrom the first end 54 to the second end 56. In some embodiments, theslit, 64 extends into at least part of the extension arms 58. The slit64 can allow the top and bottom of the first end 54 of the extensionbody 40 to be clamped down on the eyelet, and/or end of the shockabsorber, to secure the same in place within the extension body 40. Thiscan allow a rigid connection to be formed between the shock absorber 4and the extension body 40. A fastener 66, such as a bolt and nut, can beused to secure the shock absorber 4 and extension body 40 together.

Features of the extension body and shock absorber can substantiallyprevent rotation between these two mating bodies. For example, the innersurface 62 and/or the fastener 66 can be used to substantially preventrotation. Substantially prevent rotation can include rotating less than25°, 20°, 15°, 10°, 5°, 3°, 2°, and 1°.

The extension body 40 can also include one or more slots or holes, toaccommodate certain features on or near the eyelet and the end of theshock absorber 4. For example, a slot 68 can be located at the first end54 to accommodate an adjustment control 52 such as a rebound knob,located near the eyelet. In some embodiments, a stock or custom shockabsorber 4 is provided, wherein an adjustment control 52 near an eyeletor shock end is replaced with a modified adjustment control 52, designedfor use with an extension body 40. For example, the new adjustmentcontrol 52 can be smaller, larger, longer, etc. or some other shapedifferent from the original.

Some embodiments of shock absorber 4 can have an additional outsidefluid reservoir (not shown). A hole or slot in the extension body 40,such as slot 68, can be configured to accommodate a hose for connectingthe shock absorber 4 to the fluid reservoir.

The use of an extension body 40 that can receive a number of commonlyavailable or custom shock absorbers provides great benefits to both themanufacturer and the end consumer. The extension body is interchangeablewith different shocks and therefore can be used on different bicyclesand those bicycles can be upgraded, modified or repaired to incorporatedifferent or similar shocks depending on consumer preference or asrequired. This also reduces cost for the manufacturer because differentextension bodies do not need to be manufactured for use with differentshocks and/or bikes, and custom shocks do not have to be manufactured.

The use of an extension body 40 with extension arms 58 can also bebeneficial. Extension arms can beneficially allow a bicycle manufacturerto create its own pivot point for the shock absorber, rather than beingrequired to use the rear shock absorber eyelet. For example, the surfaceof the extension arms can be used to create a stronger, more durable,and smoother connection and pivot. Instead of using the DU bushingsprovided with the stock shock, cartridge ball bearings, which aresmoother and more durable, can be used at the interface between theextension arm and the sub-frame. In addition and as mentionedpreviously, the extension arms also beneficially allow the rear shockabsorber pivot to be placed in locations that were previouslyimpossible, for example, at the sides of the tires. Also, the extensionarms allow the shock pivot points to be placed in more optimallocations. The shock absorber 4 can be placed in a compact, lowerprofile orientation within the frame and still achieve a shock leveragemotion which matches that of other bikes with a higher or not as compactorientation.

The extension body 40 can provide a robust shock absorber-extension bodyinterface. With the extension body 40 as shown and discussed above, theconnection between the extension body and the eyelet is strengthened byrotating the eyelet 90 degrees to its typical orientation. In someembodiments, the extension body can be configured to receive an eyeletrotated between 80-100°, 60-120°, 40-140°. This can include anglebetween the axis of at least 15°, 30°, 45°, 60°, 75°, 80°, 85°. This canreduce the interface strength requirements and prevent the tendency ofthe shock absorber-extension body interface to rotate or buckle. Thereis a reduced propensity to rotate about the typical eyelet axis(parallel to A₂) at the interface because the eyelet is perpendicular,or at least not parallel, to its typical orientation.

In addition, the extension arms further reduce the propensity of theinterface to rotate about the axis A₁ of the new eyelet orientation.This is because of the wide bracing provided by the extension body whichcan form a wide v-shaped or y-shaped yoke. The wide bracing reduces thetendency of the interface to rotate about the new eyelet axis A₁.

Rotating or modifying the shock absorber 4, so that the eyelet 50 isrotated 90 degrees from its typical position, can also beneficially movecertain of the adjustment controls 52 to the side. Having adjustmentcontrols 52 on the side of the bicycle can have many benefits. Forexample, the user can visually and clearly see the adjustments beingmade. If the user is standing next to the bicycle making theadjustments, they are likely to be on the side of the bike and will beable to easily see the adjustments being made. They will have a clearunobstructed view of the adjustment control 52 plus any settingmarkings. If the user is on the bike, it is easy for them to reach downand make an adjustment with a normal rotational movement of their hand.

Referring now to FIG. 5, a system for securing the shock absorber 4 andthe extension body 40 is shown. In some embodiments, a fastener 66, suchas a bolt can be used to secure the eyelet 50 within the extension body40. The fastener 66 can have an outside diameter that fills or issmaller than the eyelet 50. As shown, the fastener 66 is smaller thanthe eyelet 50 and a spacer 70 is used to create a tight fit between thefastener and the eyelet. It can be desirable to provide a rigid andsecure connection between the shock absorber 4 and the extension body40. The fastener, the fastener and spacer and/or other features can beused to create a rigid and secure connection.

The extension body 40 can include a hole 74 for the fastener to passthrough (See FIG. 4). The hole 74 can pass through all or part of theextension body 40 and can pass through any of the top, bottom and/orsides of the extension body 40. As shown, the hole 74 passes from thetop to the bottom. In other embodiments, the hole 74 can pass throughthe side or at an angle. In some embodiments, part or all of the hole 74is threaded or unthreaded.

The spacer 70 can be placed within the eyelet 50 and the eyelet 50 canthen be advanced into the cavity defined by the inner surface 62 in theextension body 40. The spacer 70 can also have a hole 72 for thefastener 66 to pass through. As already mentioned, the fastener 66 cansecure the spacer 70, and thereby the eyelet 50, within the extensionbody 40.

The hole 72 in a spacer 70 can determine where the fastener 66 passesthrough the eyelet. Generally, the eyelets of a typical shock absorberare round. The spacer 70 can also be round or other shapes that can fitwithin the eyelet. The hole 72 in the spacer 70 can be centered with thespacer or off-center. Thus, with a fixed hole 74 in the extension body40, the hole 72 in the spacer and within the eyelet can determine wherethe fastener passes through the eyelet and can thereby determine aspatial relationship between the shock absorber and the extension body.

A spacer 70 with an off-center hole 72 can also be used to adjust therelationship of the shock absorber 4 and the extension body 40. Thespacer in some embodiments can be placed within the eyelet so as to lineup with the hole 74 in one of two positions. The two positions of thespacer can be about 180° apart. In one position, the hole 72 can bepositioned to be closer to the first end 54 and in another position, thehole 72 can be positioned to be closer to the second end 56. In thisway, the position of the hole 72 within the eyelet 50 can be used tolengthen or shorten the total length of the shock/extension bodycombination. In some embodiments, the spacer 70 can include more thanone hole 72. The different holes can be different distances away fromthe center or sides of the spacer. Selection of which hole 72 in thespacer 70 to use can then determine the total length of theshock/extension body combination.

In some embodiments, the extension body 40 can include two or more holes74, so that the selection of the particular hole 74 can be used toadjust the relationship of the extension body 40 and shock absorber 4.In addition, a spacer 70 with an off-center hole 72 can be used tofurther increase the adjustability of the extension body and shockabsorber positions within the particular selected hole 74.

By changing the length of the shock/extension body combination, the rearsuspension linkage extends or compresses its neutral static state. Thebyproduct of this is the raising or lowering of the crank height, orsteepening or slackening the steering geometry. These geometryadjustments are favorable to setting up the handling characteristics toindividual rider preferences.

In these ways, a simple, light weight, and unobtrusive system can beprovided to simply and cleanly adjust the frame geometry.

In some embodiments, the fastener 66 and hole 74 can be used to preventrotation of the extension body and shock absorber, instead of or inaddition to the inner surface 62. In some embodiments, the inner surface62 can be used simply to maintain the eyelet within the cavity definedby the inner surface 62. As disclosed, both the fastener 66/hole 74combination and the inner surface 62 are used to prevent rotation anddistribute forces over a wider surface area.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. Additionally, it is contemplated that various aspects andfeatures of the invention described can be practiced separately,combined together, or substituted for one another, and that a variety ofcombination and sub-combinations of the features and aspects can be madeand still fall within the scope of the invention. Thus, it is intendedthat the scope of the present invention herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims.

1. A bicycle assembly comprising: a main frame comprising a seat tube, ahead tube and an intermediate tube connecting the seat tube and the headtube; a sub-frame configured to rotate with respect to the main frame; ashock absorber having first and second opposing ends and first andsecond eyelets at each end, the first eyelet at the first end connectedto the main frame; and an extension body comprising a first endconnected to the shock absorber at the second eyelet and a second endcomprising a pair of extension arms, each extension arm connected to thesub-frame, wherein a rear pivot of the shock absorber is defined by aconnection point between each extension arm and the sub-frame, and therear pivot configured to be at the sides of a rear wheel; wherein thefirst end of the extension body receives the second eyelet within theextension body and the axis of the center of the second eyelet is atleast about 15 degrees offset from the axis of the center of the firsteyelet, such that the extension body forms a rigid, non-rotatingconnection with the second eyelet.
 2. The bicycle assembly of claim 1,further comprising a fastener securing the extension body and the secondeyelet of the shock absorber.
 3. The bicycle assembly of claim 2,further comprising a spacer within the second eyelet, the spacer havinga hole to receive the fastener.
 4. The bicycle assembly of claim 3,wherein the hole in the spacer is off-center such that the position ofspacer within the eyelet allows for the adjustment of the length ofcombined shock absorber and extension body.
 5. The bicycle assembly ofclaim 1, further comprising a fork, a saddle, the rear wheel and a frontwheel.
 6. The bicycle assembly of claim 1, wherein the sub-framecomprises a pair of seat stays and a pair of chain stays.
 7. The bicycleassembly of claim 1, wherein the axis of the center of the second eyeletis at least about 45, 60, or 80 degrees offset from the axis of thecenter of the first eyelet.
 8. A bicycle assembly comprising: a bicycleframe comprising: a main frame comprising a seat tube, a head tube and atop tube connecting the seat tube and the head tube; a sub-frameconfigured to rotate with respect to the main frame; a shock absorberconfigured to regulate the relationship between the main frame and thesub-frame, the shock absorber comprising a first eyelet to connect tothe main frame and a second eyelet; and an extension body having a firstportion configured to connect to the second eyelet of the shock absorberand form a rigid non-rotating connection, and a second portion, thesecond portion comprising a pair of extension arms; wherein theextension arms are configured to straddle a rear wheel such that a rearpivot of the shock absorber is at the sides of the rear wheel, the frontpivot being at the first eyelet of the shock absorber.
 9. The bicycleassembly of claim 8, wherein the second eyelet is perpendicular to theaxis of rotation of both the front and rear pivots.
 10. The bicycleassembly of claim 8, wherein the second eyelet is offset 90 degrees fromthe first eyelet.
 11. The bicycle assembly of claim 8, furthercomprising a fastener to secure the extension body and the second eyeletof the shock absorber.
 12. The bicycle assembly of claim 11, furthercomprising a spacer within the second eyelet, the spacer having a holeto receive the fastener.
 13. The bicycle assembly of claim 12, whereinthe hole in the spacer is off-center such that the position of spacerwithin the eyelet allows for the adjustment of the length of combinedshock absorber and extension body.
 14. The bicycle assembly of claim 13,wherein the extension body comprises two or more extension body holesfor receiving the fastener and allowing for further adjustment of thelength of combined shock absorber and extension body by selection of theextension body hole.
 15. The bicycle assembly of claim 8, wherein thesub-frame comprises a pair of seat stays and a pair of chain stays. 16.The bicycle assembly of claim 8, further comprising a fork, a saddle,the rear wheel and a front wheel.
 17. A bicycle assembly comprising: amain frame comprising a seat tube, a head tube and a top tube connectingthe seat tube and the head tube; a sub-frame configured to rotate withrespect to the main frame, the frame being configured to regulate therelationship between the main frame and the sub-frame with a shockabsorber having a first eyelet for connecting to the main frame and asecond eyelet; an extension body having a first portion configured toconnect to the second eyelet of the shock absorber and a second portion;a fastener to secure the extension body and the second eyelet of theshock absorber; and a spacer configured to reside within the secondeyelet, the spacer having an off-center hole to receive the fastener,such that the position of spacer within the eyelet allows for a user toadjust a length of the shock absorber and extension body.
 18. Thebicycle assembly of claim 17, further comprising the shock absorber,wherein the second eyelet is perpendicular to an axis of rotation of thefirst eyelet.
 19. The bicycle assembly of claim 17, further comprisingthe shock absorber, wherein the second eyelet is offset 90 degrees fromthe first eyelet.
 20. The bicycle assembly of claim 17, wherein theextension body comprises two or more extension body holes for receivingthe fastener and allowing for further adjustment of the length ofcombined shock absorber and extension body by selection of the extensionbody hole.
 21. The bicycle assembly of claim 17, wherein the secondportion of the extension body comprising a pair of extension armsconfigured to straddle a rear wheel such that a rear pivot of the shockabsorber is at the sides of the rear wheel, the front pivot being at thefirst eyelet of the shock absorber.
 22. The bicycle assembly of claim17, further comprising a fork, a saddle and two wheels.